Re: Google maps does all this already...
What I really like of the phone version is that it checks the route for traffic jams and tries to reroute me if possible
Built in satnavs commonly do that now.
I guess built in satnav will be like electric windows. Once rare and expensive but now the norm. Soonish it will be everywhere except in the cheapest cars (and nothing wrong with that). My main problem with phone/tablet nav is having to install it for every journey, and having to operate a touch screen while driving. On the other hand, built in maps tend to get annoyingly out of date.